It is known to have a mechanical or electronic control of coolers, especially coolers for beverages, said control adjusting the temperature during a certain period of time, e.g. during a week, so that the temperature of the coolers are adjusted to a lower temperature during opening hours of a store, and so that the temperature is adjusted to a higher temperature during closing hours of the store. Thereby saving electrical energy for the compressor used in the cooler is obtained. A timer schedule is set up taking into account actual opening hours and closing hours of the store, said schedule being followed during a prolonged period of time, such as half a year when the timer schedule possibly needs to be adjusted due to day-time saving, or other irregularities during a calendar year in the country where the cooler is situated, or due to differentiated opening and closing hours of the store.
A problem may be that there are periods during the day, where the store is open, but where the sale of food and/or beverages nevertheless is absent. Food and/or beverages being cooled to a lower temperature, resulting in a higher electrical energy consumption, although the food and/or beverages may be stored at a higher temperature, during absent sale, which would result in a lower electrical energy consumption, thus a consumption of electrical energy during opening hours which is not needed due to the absent sale.
It may be an object of the invention to reduce the electrical energy consumption of refrigerators, not only during closing hours, but also during opening hours. It may alternatively be an object of the invention to reduce the electrical energy consumption of domestic refrigerators during hours of the day, where food and/or beverages are not inserted into or retracted from the refrigerator for consumption.